This invention relates to the field of metal-cutting tools, and more specifically, to milling cutters.
In those types of milling cutters having indexable inserts, each insert is clamped into a pocket of the cutter body by a wedge clamp, several of which are well known in the prior art. Most of the inserts so used in milling cutters are made from cemented carbide material.
During the manufacture of the milling cutter, and more particularly, the machining of the insert pockets and clamp recesses as well as the clamp itself, various tolerances are created. The more surfaces that are machined, the more tolerances that are created. While some tolerances may cancel each other out, other tolerances may add together so as to result in a cumulative tolerance.
When the insert is placed in the insert pocket and the wedge applied, this cumulative tolerance may prevent the wedge face from making planar contact with the insert. Instead, the wedge may meet the insert along a line, or perhaps even at a point. With cemented carbide inserts, this nonplanar contact is not a problem since cemented carbides have a certain amount of toughness which allows them to withstand nonplanar contact.
On the other hand, if ceramic inserts are used, as is often the case today, a serious problem is encountered. Ceramic inserts are extremely brittle. If there is nonplanar contact between the wedge face and the insert, as is possible with conventional clamping means, the insert may crack.
It would, of course, be desirable to be able to clamp a ceramic insert without causing it to crack.
It is thus an object of this invention to have a means of clamping a ceramic insert without causing it to crack.
It is another object to have a clamp in which there is always planar contact between a surface of the clamp and the insert.
It is a further object to have a clamp that is simple to use and manufacture as well as economical to buy.
It is a still further object of this invention carbide inserts as well as ceramic inserts. to have a clamp that is usable with cemented